Tie member for concrete forms



Dec. 9, 1924. 1,518,955

K.BACKLUND TIE MEMBER FOR CONCRETE FORMS Filed Dec. 7, 1923 I ENTOR /W M BY Patented Dec. 9, 1924.

UNITED STATES KNUTE BACKLUND, OF PITTSBURGH, PENNSYLVANIA.

TIE MEMBER FOR CONCRETE FORMS.

Application filed December 7, 1923.

To all whom it may concern:

Be it known that I, KNUTE BAGKLUND, a citizen of the United States, and a resident of Pittsburgh, in the county of Alla gheny and State of Pennsylvania, have made new and useful Improvements in Tie Members for Concrete Forms, of which the following is a specification.

The invention relates to tie or brace members for holding the form members between which concrete is poureo in constructing concrete walls. The invention has for its principal objects the provision of an improved tie member or fastener (1) which has a maximum degree of strength in proportion to its weight and cost, (2) which is easily put in place and in which the part of the device which remains in the concrete is relatively cheap. One embodiment of the invention is illustrated in the accompanying drawing wherein:

Figure 1 is a section through a concrete wall and the form members supporting it with the improved tie member in position therein. Fig. 2 is a perspective view of the two hook members constituting one of the stirrup members. Fig. 3 is a side elevation of the two hook members in assembled position. Fig. 4 is a side elevation showing a modified form or stirrup construction in assembled relation with its cooperating parts. And Figb is a perspective view of the stirrup of Fig. 1.

Referring to the drawings the form members illustrated consist of the usual boards or planks 1 supported by the spaced vertical stringers 2 and the transverse beams 3.

Extending through the beams 3 are the rods 4, 4c threaded at their ends and provided with the nuts, 5. 5 and 6, 6. At the inner ends of each rod is a stirrup which may be formed in various ways. but preferably consists of a pair of hook members 7 and 8, which are nested together as indicated in 3. The rod extends through the loops 9 and 10 of these members. while the hook 11 on the member 7 fits inside the book 12 on the member 8.

The two stirrups are secured together by means of a tie consisting of a plurality of turns or lengths of steel wire 13. The number of the strands of wire and its size will depend on the character of the work and the strain imposed upon it, but preferably this wire is relatively thin or light so that it may be bent easily, and so that a larger deselial No. 679,252.

gree of strength in proportion to the weight of the Wire may be secured. The strength of this wire connection need not be as great as that of the rods 4, 4:, as the wire is sub-- ject to strain for only a relatively short time, while the rods are used repeatedly. As a specific example, if rods of three fourth inch diameter are used, 36 strands of No. 16 steel wire may be employed to advantage or 2 1 strands of No. 14 wire or 1 1 strands of No. 12 wire, the total strength of tie member being approximately the same in all three cases.

The hook members are made of heavy steel wire, preferably about five sixteenths of an inch in diameter for use with three fourth inch rods. The two hooks 11 and 12 reinforce and support each other and their resistance to straightening, when tension is applied to the tie member is materially increased by reason of the fact that the two books face each other, the hook 11 being held from movement to the right (Fig. 3) by the straight back portion of the member 8.

The sides of the hook members engage the sides of the nuts 6 and prevent them from turning as the rods are secured into position while the ends of the hooks 11 enthe ends of the rods. as indicated in Fig. 1, (see also 1) and act as stops for preventing further inward movement of the rods, so that they are held against turning when the nuts 5, 5 are screwed in to apply {)he necessary tension to tighten the tie mem- In assembling the tie, the bundle of turns 13 (preferably made u of a single wire) is prepared outside the form by winding the wire around two posts or supports separated a distance equal to approximately the distance between the two stirrups to be connested. The tie. as thus formed, is slipped over the two hook members 7 and 8 which are alongside each other. but separated latorally to permit this being done conveniently after which the members are nested (Fig. .5) the nut 6 is positioned inside the members, and the rod 4 screwed into the nut, after which the parts are similarly assembled at the other-end of the tie. The nuts 5, 5 are then screwed in till the necessary tension is applied to the tie.

Figs. 4 and 5 illustrate a modification in which the stirrup 1 1 is made of a single piece having the two hooks 15 and 16, which fit over each other the same as in the first construction, a space 17 being provided for the insertion of the wire between the hooks. IVith. this construction the Wire must be applied strand by strand after the stirrups have been secured to the ends of the rods 4, which is a more tedious operation than that required with the stirrup construction of Figs. 2 and 3, in the use 01": which, as heretofore explained, all the wires constituting the tie can be attached to the stirrup at one time.

The construction, as shown and described presents a number of mechanical advantages. The ties of relatively light wire, while more expensive pound for pound than solid tie rods or heavv wire. are several times as strong poundfor pound, so that the cost is much less than heavv ties. Similarly, the stirrups are relatively. cheap as comp red withcast stirrups because or their relatively light weight as the cost cit bending by suitable dies and machinesis negligible. The wire tie is also preferable to heavier ties o'f'larger cross section in cases where the wall is designed to retain Water, as the seepage along the wires is much less. The wire tie also has an erection advantage as it-fcan be coiled and bent in getting it to its, position of use, thus making 'it easy for the workmen to avoid interference with the network of reinforcing in the form of bars and rods, such as is often found in concrete wall construction and which makes it difiicult to position rigid or relatively stitt tie rods. @ther advantages will be apparent to those skilled in the art. 1 What I claim is:

1,. In combination in a tie member tor concrete, a pair of stirrup members provided with loops and hooks, a tie consisting of a number of'turns of relativelv light Wire engaging the hooks on the stirru'ps, nuts lying'in the stirrups and held against turning thereby, rods extending through the loops'in the stirrups and threaded into the nuts, and also being threaded at their other ends, and nuts on said other ends;

2. In combination in a tiememher for concrete, a pair of stirrup members of heavy wire provided with loops and hooks and also with reinforcing means for supporting the hooks against straightening; when tension is applied thereto, a tie consisting of a number of turns of relativelv light wire engaging the hooks on the stirrups, nuts lying in the stirrups and held against turning thereby. rods extending through the loops in the stirrups and threaded into the nuts,'an'd also being threaded at their other ends, nuts on said other ends.

- 3. In combination in a tie member for concrete, a pair of stirrup members of heavy wire provided with loops and hooks and also with overlapping reinforcing turns for supporting the ho'oks against straightening under tension, a' tie member engaging'the hooks, and tightening rods extending through the loops of the stirrups and secured releasably therein.

4. In combination in a tie member for concrete, apairot stirrup members of heavy Wire provided with loops and hooks and also'with overlappingreinforcing turns for supporting the hooks against straightening under tension, a tiemember engaging the hooks, nuts in the stirrups prevented from turning thereby, and tightening rocs ex" tending through the loops of the stirrups and threaded into the nuts. I

In combination in a tie member for concrete, a pair of stirrup members formed by doubling a heavy steel wire and bending it sons to form a loop at one end and a hook at the other, a tie member engaging the hooks, and tightening rods extending through the loops and secured releasablv therein.

'6. A stirrup for a concrete tie member comprising a'pair of Wrought metal'hook members each provided with a loop at me end'and a hookat the other and nested one insidethe other facing in opposite directionswith the loops overlapping.

'2. A. tie member. 'for concrete comprisi' a pair of stirrups each consisting of a pair of wrought metal hook members; each provided with a loop'at one end and-a hook at the other and nested one inside the other facing in opposite directions with the loops overlapping, a flexible tie secured at its ends to the hooks on the two stirrups and comprising a plurality of turns of wire. a nut in each stirrup, and threaded tighter ing' rods extending through the loops on the hooks and into the nuts. I In testimony whereof, I have llBIElUltO subscribed my name this lth' day of Dec.

.. KNUTE BACKIJUND. 

